DOVER, Florida — The law of supply and demand had worked pretty well for the Florida strawberry industry during the past decade.

This season, not so much.

A supply spike of fresh strawberries hit the U.S. market this winter, driving down the retail price for consumers but also farm prices. Florida strawberry growers will struggle to turn a profit this year.

"The prices have been way too cheap. This has been a good year for consumers, both in quality and price," said Mike Lott, a Seffner strawberry grower with 42 acres. "We've been picking cheap all year."

Lott and other strawberry growers still don't know if they'll end the season next month with a profit.

"It's going to be tough. It's going to be down to the wire," he said.

Andy McDonald, owner of Sweet Life Farms, which has 92 strawberry acres in Plant City, agreed.

An unseasonably warm winter in Florida had strawberry plants producing at record capacities, the growers said.

But the Mexican strawberry industry, expanding for the past several years, also enjoyed unusually good growing conditions, they said. Because Mexican growers use the same strawberry varieties as Florida, which produce from late November to March, cheaper Mexican strawberries came into the U.S. market in unprecedented numbers, driving down U.S. prices.

"We're facing unfair competition," said Gary Wishnatzki, CEO at Wish Farms Inc., a Plant City strawberry grower and the state's largest shipper of fresh strawberries. "The market would have absorbed our production if it were not for Mexico."

Wishnatzki and the other growers complained Mexican strawberry farms face much lower labor and production costs, making it difficult to compete on price.

Many regular customers stopped buying from Wish Farms, telling Wishnatzki they would go with the cheaper Mexican strawberries, he said.

"The [supermarket] chains started buying Mexican product because it was heavily discounted," Wishnatzki said.

From mid-November through Feb. 18, Mexico shipped 97.3 million pounds of strawberries to the U.S., a 26.2 percent increase from 77 million pounds in 2010-11, according to U.S. Department of Agriculture statistics.

The bigger concern, however, is that this year's strawberry market may have become the new normal, they said.

"Over the years, it's been a competition between California and Florida," Lott said. "Now we've got Mexico in the mix."

The Florida strawberry industry built itself on two pillars -- rising consumer demand for strawberries because of perceived health benefits and a climate that gives Florida an exclusive market window as the nation's provider of fresh strawberries from that first harvest in late November to March.

U.S. consumption of fresh strawberries doubled from 2 pounds per capita in 1980 to about 4 pounds in the early 1990s, USDA statistics show. Then it surged again to 7.2 pounds in 2010, the latest data available.

This year Florida has more than 10,000 strawberry acres, said Ted Campbell, executive director of the Florida Strawberry Growers Association in Dover.

That first month of harvesting in December set the tone for the season, Campbell and the growers said. Christmas, along with Valentine's Day, is a sales peak for Florida strawberries.

Because of its exclusive market window, growers in past seasons could count on a wholesale price of $15 to $20 a flat for their strawberries in December, they said. The price would fall to about $12 to $15 a flat during January and February, but that was still above the growers' break-even point, currently about $6 to $7 a flat.

In a typical year, most Florida growers stop harvesting in March, when the price falls below the break-even point because of the influx of California strawberries.

California is the largest U.S. strawberry producer with 34,608 acres, according to the California Strawberry Commission, but its production falls off dramatically in December and January. In February and March, production rises only enough to supply mostly markets west of the Mississippi River.

Because of Mexican imports this season, the wholesale strawberry price fell to $7 a flat the week before Christmas, Campbell and the growers reported. The price recovered to about $12 in March but fell again just before Valentine's Day.

Friday's prices for Florida strawberries were mostly $7.90 to $8.90 a flat, the USDA reported. Demand remained "good."

At those prices, the only avenue to profitability for the 2011-12 season is picking large volumes of strawberries through March, Lott and McDonald said.

"We will have to pick an extreme amount of strawberries [in March] to break even," said McDonald, the Strawberry Association president. "I'm optimistic that we'll pick a lot of strawberries."